BME Seminar Series: Mark Calhoun, Lauren Eichaker, Peter Amaya, & Andrea Wanamaker

Mark Calhoun:

"Hydrostatic Pressure Induces Glioblastoma Cell Death in Tumor Edema Model"

Glioblastoma is the most lethal form of brain cancer, with a median survival time of 15 months even with surgery, radiation, and chemotherapy. The lethality of the cancer is exacerbated by the diffuse nature of the tumor, which results from extensive, unchecked migration of the tumor cells. As the tumor cells migrate throughout the brain, they deform the natural brain structures, inducing physical forces that act on the tumor cells. Specifically, tumor cells migrating along blood vessels disrupt the vessels, and induce the formation of new blood vessels, resulting in edema, or an elevated fluid pressure within the brain. We are interested in how this physical stimulus (i.e. hydrostatic fluid pressure), induced by the tumor, affects tumor survival akin to a feedback loop. By understanding the molecular mechanisms underlying tumor death in response to hydrostatic pressure, we aspire to show, for the first time, that a physical force in the tumor microenvironment can be combined with an intervention to destroy tumor cells and enhance patient survival.

Lauren Eichaker:

"Analysis of Injury Mechanisms and Outcomes within Common Crash Scenarios – CIREN Studies"

“Lead vehicle stopped” (LVS), “vehicle(s) turning at non-signalized junctions” (NSI), and “changing lanes on the highway” (CLH), are among the top five of NHTSA’s thirty seven pre-crash scenarios in terms of frequency, years lost, and economic cost (Najm, 2007). These three pre-crash scenarios account for $120 billion in economic cost and 3 million functional years lost combined (NHTSA DOT HS 810 767).

In the LVS crash scenario a vehicle is going straight, at an intersection-related location and closes in on stopped lead vehicle; speeding and inattention are important factors (Najm, 2007). LVS accidents represent $15 billion of the total economic cost and 9% of functional years lost (approximately 240,000 years). It is the most frequent of the 37 crash scenarios (NHTSA DOT HS 810 767). The third most frequent of NHTSA’s 37 pre-crash scenarios are near side impact (NSI) crashes (referred to as “vehicles turning at non-signalized junction” by NHTSA). This type of pre-crash scenario accounts for 5% of the functional years lost and $7 billion of the total economic cost (Najm, 2007). Lane change accidents that occur on highways, or during merging account for $4 billion in economic cost and 3% of the functional years lost of the 37 crash scenarios. It is the sixth most frequent type of crash, but most of these crashes result in loss of property, not injury (NHTSA DOT HS 810 767). CLH crashes may involve multiple cars at higher speeds on highways, making analyses more difficult.

Following LVS, NSI, and CLH impacts, drivers may be disoriented and/or injured. This may inhibit their ability to optimally control their vehicle. Additionally, once an initial crash occurs, vehicular crumple zones may be exhausted, safety technologies that deployed during the first impact are unavailable for subsequent impacts, and occupants may be out of position. The primary goal of this study is to gather and analyze LVS, NSI, and CLH cases from Crash Injury Research Engineering Network (CIREN) to document trends of injury mechanisms. Common crash characteristics that lead to these injuries (e.g. PDOF, deltaV, seatbelt usage) will also be investigated. These trends will be used to suggest driver positional changes, evasive actions and/or occupant-centric semiautonomous vehicle behaviors best suited to reduce injuries.

Peter Amaya:

"CTC enrichment optimization reveals cytokeratin positive (CK+) efferocytes that contribute to cancer progression"

Mammalian cell bioprocessing is a critical part of both diagnostic and therapeutic applications. In terms of diagnostics, blood based biomarkers can be isolated from the peripheral blood and analyzed to help clinicians make informed decisions regarding treatment. Three blood based biomarkers that have gained a lot of attention recently are circulating tumor cells (CTCs), circulating tumor DNA (ctDNA) and extracellular vesicles (EVs). Among these, CTCs provide the most information as they are a whole intact tumor cell. Bioprocessing of CTCs; however, is very challenging as one these cells circulates among 10 million leukocytes. Like primary tumor cells, these cells exist as a heterogeneous population, further complicating their analysis.

Andrea Wanamaker:

"Comparative biomechanical analysis of upper limb movement of partial-hand amputees and healthy two-handed controls"

There are currently two million amputees living in the United States with 35 percent living with loss of an upper limb. As the function of the hand is essential for communication, self-care, and daily tasks, amputation involving the upper limb can result in severe functional deficits, particularly if the thumb or multiple digits are lost; however, the use of an externally powered hand prosthesis can potentially restore user function. Clinical practice guidelines offer little help in determining the best prosthesis for an upper-limb amputee and amputees are often prescribed a prosthesis that does not match their goals or needs due to prohibitive costs. The lack of research on more expensive externally powered devices results in a lack of evidence that these devices may be more beneficial to the user. The objective of this investigation was to evaluate partial-hand amputees (4-digit amputees with an intact thumb or 5-digit amputees) performing various tasks of daily living with and without their externally powered hand prosthesis. Upper limb biomechanics of healthy two-handed upper limb movement were also examined in order to provide data for comparative analysis, as well as to determine differences within the healthy cohort: dominant vs non-dominant upper limb movement.